CAIE A Level Biology 9700 · Immunity
A person is infected with a novel strain of influenza virus (antigen A). After recovery, several months later, the person is exposed to the same strain again. Compare the immune response during the first infection (primary response) with that during the second exposure (secondary response), explaining the role of memory cells in the observed differences.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Compare means: Give similarities or differences between two things, and say which side each point belongs to. Write each point as a pair, for example: A is X, whereas B is Y. Two separate descriptions rarely earn the marks.
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